Catalyst for the production of polyester, use of the catalyst for the production of polyester, and polyester obtained by the use of the catalyst

Abstract

The present invention relates to a catalytically active composition that can be used for the production of polyesters. According to the invention, good polyester products can be obtained in this way without having to use antimony components.

Description

BACKGROUND[0001]1. Technical Field[0002]The present invention relates to a catalyst suitable for the production of polyester, use of said catalyst, and a method of production using the catalyst.[0003]2. Description of the Related Art[0004]The production of polyesters generally takes place by means of reacting a diol with a dicarboxylic acid or a low dicarboxylic acid ester, for example, a dimethyl ester, to form the corresponding dicarboxylic acid ester, which is polycondensed at rising temperatures and reduced pressure in a single stage or in multiple stages. Various catalysts are used for the esterification and / or the transesterification and polycondensation, depending on the selection of the diols or the dicarboxylic acids or dicarboxylic acid esters.[0005]Generally in this process, a catalyst is used that comprises the polyvalent metal cations, which are able to form transition complexes with the functional groups, particularly with the hydroxyl terminal groups, whereby preferre...

AI Technical Summary

Benefits of technology

[0012]The object presented above is solved by the subject matter of Claim 1 of the present application. Preferred embodiments are listed in the dependent Claims 2 to 11 and in the following description. The present invention furthermore provides a method, as defined in Claim 12, for the production of polyester. Preferred embodiments of this method

Problems solved by technology

Particularly with respect to the catalytically active component Sb3+, however, it is detrimental that this can possibly exercise harmful influences on the environment.

Detrimental with regard to the use of Ti as a catalytically active metal component in catalysts for polycondensation of polyesters, however, is the high level of sensitivity to hydrolysis, for example, of the customary titanium alkoxides and the tendency towards precipitation that is inherent in compounds of this type, as well as the ability of producing colored complex compounds, which have a detrimental effect on product quality.

Furthermore, catalytically effective compositions based on titanium are not able to show sufficiently high activity in the solid state during polycondensation in the manufacture of polyester, whereby this is a process step that is particularly necessary for the production of polyester materials for packaging purposes.